Impressive Magpies down Eagles in Perth

Collingwood defender Ben Reid faces a nervous wait after injuring his right knee in Sunday's 20-point pre-season cup victory over West Coast at Subiaco Oval.

Reid limped off the field in the third quarter after jarring his right leg when a falling Josh Kennedy crashed into him.

The 2010 premiership defender was plagued by quad injuries early last AFL season and has just four weeks to prove his fitness for the club's season opener against North Melbourne on March 31.

The Eagles were also struck by injuries, wingman Andrew Embley damaging his right hamstring and Matt Rosa finishing the game on the bench with an ice pack on his right hamstring.

Although the treatment for Rosa was precautionary, Embley's seemed more serious, with the 2006 Norm Smith medallist facing a race against time to be fit for the March 23 opener against Fremantle.

Collingwood's 3.10.9 (96) to 1.10.7 (76) triumph was its third straight win of the preseason.

The Magpies will reach the final if they can beat Brisbane in Saturday night's clash at Docklands.

Collingwood was well served by Scott Pendlebury, Paul Seedsman, Alan Toovey, Heath Shaw and Dane Swan.

West Coast forward Mark LeCras booted four goals in just his second match back from a knee reconstruction, while skipper Darren Glass was strong in defence and Scott Selwood tallied 29 possessions and a super goal.

Collingwood entered the match missing more than half of its first-choice side, with the likes of Luke Ball, Dayne Beams, Alan Didak, Darren Jolly, Dale Thomas, Andrew Krakouer and Clinton Young among a host of players absent.

But the Pies' greater work rate and hardness at the ball proved the difference, with their pressure in the forward half a particular highlight.

The Eagles, who take on Port Adelaide in Alice Springs on Saturday, are out of the running to reach the cup final after winning just one of their three games.

Former West Coast forward Quinten Lynch was solid for Collingwood, spending time up forward and in the ruck.

In other games, St Kilda defeated the Sydney Swans by 23 points at Docklands, and Melbourne defeated Port Adelaide by two points in Renmark.

The Saints trailed for much of the game before kicking five final quarter goals to one to beat Sydney 0.13.12 (90) to 1.8.10 (67).

St Kilda spread the load with 10 different goalkickers - Trent Dennis-Lane kicked two against his former side, and Ahmed Saad and Samuel Dunnellalso bagged two each.

For the Swans, Andrejs Everitt and Jake Lloyd led the way with two goals each.

In Renmark, Port Adelaide was never in front in the entire game, but the team kicked three unanswered goals - including a super goal from Hamish Hartlett to rattle the Demons after trailing by as much as 25 points midway through the final term.

The final score saw the Demons home 0.12.6 (78) to 1.10.7 (76).

For Melbourne, James Sellar kicked five goals and Aaron Daveygrabbed three, while Daniel Stewart led the way for the Power with three majors.